Question: Simplify the following expression: $q = \dfrac{t}{10} - \dfrac{3t}{2}$
Answer: In order to subtract expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $10$ and $2$ $\lcm(10, 2) = 10$ $ q = \dfrac{1}{1} \cdot \dfrac{t}{10} - \dfrac{5}{5} \cdot \dfrac{3t}{2} $ $q = \dfrac{t}{10} - \dfrac{15t}{10}$ $q = \dfrac{t -15t}{10}$ $q = \dfrac{-14t}{10}$ Simplify the expression by dividing the numerator and denominator by 2: $q = \dfrac{-7t}{5}$